Richard Stead, CEO of Qures Group, discusses the century-long history of Hypothiocyanite and the Lactoperoxidase System, and their modern potential in the fight against AMR.
In late 2012, I set out deliberately to understand how nature protects the body at its most vulnerable entry points. I was searching, without knowing the name, for a natural antimicrobial molecule capable of preventing pathogens from entering through the eyes and mouth.
These sites are moist, nutrient-rich, and constantly exposed to the environment, yet infections there are surprisingly rare. Something must be working with a competence comparable to that of the skin.
What I eventually found was Hypothiocyanite (OSCN⁻), a molecule I had never encountered before. To my surprise, it had already been described a century earlier. Its biology and chemistry had been mapped decades before I began my search, yet its relevance, power, and potential remain profoundly under-recognised.
This article provides a concise historical overview of the discovery of Hypothiocyanite and the Lactoperoxidase System (LPS), explaining why this natural defence mechanism is so critical in an era of rising antimicrobial resistance (AMR).
Nature’s defence: A single broad-spectrum molecule
In medicine, pathogens are classified into three major groups: bacteria, viruses, and fungi. Each requires different classes of drugs, and patients infected with multiple pathogens often need several treatments. Nature, however, has a simpler, more elegant approach.
Across saliva, tears, airway secretions, and milk, a single molecule – Hypothiocyanite – is produced precisely where and when it is needed. It provides broad-spectrum antimicrobial protection without harming host tissues.
Nature’s solution demonstrates that chemistry, carefully tuned, can be as powerful as it is safe.
Understanding how hypothiocyanite is made: The Lactoperoxidase System (LPS)
Once I discovered Hypothiocyanite, my next task was to understand how it is generated. The answer lies in a natural enzyme system:
Lactoperoxidase (LPO) + Thiocyanate (SCN⁻) + Hydrogen Peroxide (H₂O₂) → Hypothiocyanite (OSCN⁻)
This system operates continuously in secretions that protect our mucosal surfaces. Its chemistry is elegant, efficient, and activated only when pathogens are present.
I also began to explore whether this system, so effective in nature, could be replicated, stabilised, and delivered to sites of infection, especially those caused by antimicrobial-resistant strains. I wondered why such a powerful natural mechanism had never been fully commercialised. Studying the history of the LPO system helped explain this.
Historical timeline: From “lactenin” to Hypothiocyanite
In 1918, Bjerrum and Kirschner provided the first chemical description of hypothiocyanous acid – the protonated form of OSCN⁻. This marked the earliest known characterisation of the molecule, although its biological significance was not yet understood.
The milk antimicrobial era
By 1924, Hanssen reported that milk’s bactericidal activity varied and linked it to “oxidases and peroxidases,” which were later associated with Lactoperoxidase. Between the 1930s and 1950s, milk peroxidase was purified and recognised as a distinct enzyme. It became clear that this enzyme was not only present in milk but also in saliva, tears, and airway secretions.
Establishing the Lactoperoxidase system
In the 1960s, classic studies demonstrated that combining LPO with SCN⁻ and H₂O₂ inhibited bacterial growth, particularly streptococci. The system was mapped as an antimicrobial mechanism, though the precise active product was not yet fully identified.
Identification of Hypothiocyanite as the active antimicrobial
By the late 1970s, research showed that OSCN⁻ was the primary product of LPO-mediated oxidation of thiocyanate. In the 1980s, OSCN⁻ was detected directly in human saliva. Studies revealed that its levels rise with stimulation and that its antimicrobial action results from the oxidation of microbial sulfhydryl groups. OSCN⁻ proved effective against a broad spectrum of pathogens. During this period, the LPO–OSCN system was applied in dairy preservation, oral-care products, and food safety applications.
Hypothiocyanite in airway and systemic host defence
From the 2000s onward, research confirmed that airway epithelial cells express LPO and that OSCN⁻ contributes to normal airway defence. In conditions like cystic fibrosis, impaired thiocyanate transport reduces OSCN⁻ production, helping explain chronic infections. Reviews from the 2000s through the 2020s have consolidated OSCN⁻ as a host-derived, broad-spectrum antimicrobial and antiviral.
Modern relevance: A one-health molecule for the AMR era
The LPS system is already recognised by global authorities. The WHO and FAO recommend its use in hot climates to keep milk fresh during long transport. Milk treated with the LPS system arrives at processing plants with taste, quality, and safety fully preserved. This demonstrates a remarkable property: OSCN⁻ can protect biological fluids without harming them.
Why it matters now
As AMR grows, surgeons increasingly delay or cancel procedures due to infection risks. Humanity needs safe, effective antimicrobial systems that pathogens cannot easily resist. Hypothiocyanite – a natural defence molecule already produced by the body – fits this need perfectly.
The role of Qures Group
Qures has developed a patented platform for generating OSCN⁻ and related molecules and delivering them to sites where pathogens cause problems – in humans, animals, agriculture, water, and even air.
By reproducing nature’s chemistry in a stable, controlled form, Qures enables targeted applications that reduce microbial load without damaging host tissues. The goal is to transition the world from the current AMR era – where infections increasingly resist treatment – into a Post-ABR® era, in which natural chemistry supports safe and effective medical care. Researchers, clinicians, industry partners, and health authorities are invited to join this mission.
Conclusion
For over a century, scientific literature has revealed fragments of a natural defence system that is elegant, broad-spectrum, and inherently safe. Hypothiocyanite – produced by the Lactoperoxidase System – has protected mammals long before modern medicine existed.
Today, as antimicrobial resistance threatens global health, this ancient molecule has newfound relevance. With advancing technology, we can generate OSCN⁻ reliably, deliver it effectively, and apply it within a modern One-Health framework.
The science is old.
The timing is new.
And the need is urgent.
